To set the working directory for powershell add the following command to your PowerShell profile:

Set-Location c:\scripts

To Create a PowerShell Profile

1. Create a folder in your Documents folder called WindowsPowerShell in my case that is C:\Users\pera.virtualOne\Documents\WindowsPowerShell

2. Create a file called profile.ps1 inside this folder

3. Add any desired initialization commands to this file (Set-Location c:\scripts) and save it

4. Every time you launch PowerShell, the profile script will be executed

Copy / pasted from here.

If your powershell looks like:

param($myTestParameter)

function TestParameter()
{
	Write-Host "Parameter is: $myTestParameter"
}

Saved as myTest.ps1, for example.

Then to use parameter, call script like:

. .\myTest.ps1 -myTestParameter "Test parameter"

Notice that myTestParameter is without dollar sign, and then you can call function like TestParameter, result should be something like:

Parameter is: Test parameter

Example download from here.